Air Quality or the lack of it is a key topic of discussions in all forms of media these days. Rising
air pollution levels are being recorded not only across all major cities in the country but also in
smaller towns. There is also a greater awareness amongst the population of the ill effects of
pollutions and the sources of pollution as well. People are now aware of the impact of
Particulate Matter (PM) 10 and 2.5 in the air, a major change from a few years back when air
pollution always meant smog. With greater urbanization and rapidly expanding population of
cities and towns, the work is moving from outdoors as was the case with people employees in
agriculture, to indoors. More and more people are spending more time inside buildings and
work spaces than out one the open and hence, the quality of air within these spaces is as
important as the air outside in environment.

Ventilation plays a key role in making buildings, work spaces as well as the places we reside in habitable. Traditional
homes had natural ventilation arrangements such as openings near the ceiling to allow hot and stale air to move out as it
got displaced by the cooler outside air. Modern buildings which house large numbers of workers can no longer rely on
natural ventilation and mechanical ventilation is essential to make the space usable. Thus, ventilation of the work or
living space is critical to ensure a healthy atmosphere for the occupants.

In office ventilation systems, air gets recirculated within the work space, with only minor (5 – 10%) of fresh air being
introduced into the system. Thus, pollutants which are generated within the work space will remain in the system if not
filtered out or treated. Some of the common pollutants found in office spaces and their effect on humans are shown in
table below. In addition, good IAQ also involves having the right levels of light, correct thermal comfort and appropriate
levels of carbon dioxide.